A Lafayette man accused of killing his mother by stomping on her head terrorized and spied on the woman for months before her death last February, according to testimony his sister gave to a Boulder judge Monday.

Adam Raszynski, who is charged with second-degree murder in the death of 60-year-old Rita Redford, is in court this week for a motions hearing being held to determine to what extent witnesses claiming Redford was frightened of her son can testify at his trial in March.

Raszynski's sister, Jennifer Billings, was the star witness Monday, telling the court that her mother told her that Raszynski would take drugs, follow her around in her house on Whitetail Road, yell obscenities at her and steal from her.

Billings said her mother told her Raszynski created a hole in her bathroom wall so that he could listen in on her phone conversations.

"She said he was taking three hits of acid per day and becoming increasingly scary," Billings said, crying frequently through her testimony. "She said the place she felt safe was her room because she could lock the door."

Police said Raszynski, 33, threw his mother down the stairs Feb. 23, 2011, and stomped on her head and neck, killing her, after she shot him five times in their home in Lafayette.

Raszynski was living with his mother after being released from a Florida prison in 2009, where he served time for aggravated stalking.

Billings was one of a string of witnesses who took the stand Monday to describe Redford's condition during her final months and the dynamic living with her son produced.

Prosecutors are scheduled to call more witnesses to the stand Tuesday and Boulder District Judge Thomas Mulvahill may rule from the bench as early as Tuesday on the admissibility of their testimony.

Billings testified that in January 2011 she became so concerned for her mother's safety that she called Lafayette police from Nepal, where she was living, and asked them to check on her mother.

Lafayette police officer Robert Johnson, who was sent to check on Redford's welfare after Billings' call, said Redford appeared uncomfortable talking to him while her son was within earshot.

"At first she was really quiet, and then she seemed really afraid to tell me anything," the officer testified.

Johnson told the court that Redford said she kept a gun in her bedroom in case her son broke down her bedroom door, but he told the judge that she was unable or unwilling to articulate why she was afraid of her son. She refused to kick him out of her house, he testified, because Raszynski didn't have money or a job.

"She wasn't going to have her son sleep on the street," he said.

Raszynski's attorney, Seth Temin, asked Johnson whether Redford claimed that her son had broken down her bedroom door or ever threatened to break it down. The officer said no.

A second Lafayette police officer, Dan Tipton, testified that during the same visit to Redford's home she appeared "visibly distraught, upset and frightened."

But under cross examination, he was unable to explain why he thought she was upset beyond saying she had a certain look of discontent and spoke nervously.

A former saleswoman who sold Redford a used Subaru last February and spoke to her hours before she died testified that Redford told her that Raszynski had ripped the mirror off her Subaru out of anger.

Michelle Burgess said Redford told her that Raszynski was specifically angry that she had traded in her more powerful Volvo for a Subaru Forrester.

She told the court that Redford claimed her son had schizophrenia and bi-polar disorder.

"She said the hardest part was never knowing what would set him off," she said.

Testimony Monday ended with a couple of Redford's square dance colleagues taking the stand. Beverly Moore testified that Redford had given her a package of legal items -- safe deposit keys, lawyers' contacts and insurance information -- a couple of days before her death.

"It looked like she was a whole lot more worried about things than I thought she was," Moore said. "I don't know, I think she just kind of lost hope. Her health was bad, her situation with Adam was bad."

She said Redford was taking a lot of medication for back pain following surgery on her back in 2008.

Moore said she also heard from Redford on the phone the day she died and Redford told her Raszynski was "agitated" and walking around her Lafayette home talking to himself. Moore said she offered Redford a place to stay at her house but Redford declined.

In the last few months of her life, Redford "went from being a very social person to being a recluse," Moore told the judge.

She said Redford spent 85 percent of her time in her bedroom, ate meals on paper plates so that she wouldn't have to go back to the kitchen with dirty dishes, and suspected her son of stealing her possessions and pawning them for money.

But Moore was unable to recall any instance in which Redford said she was scared of her son.